Sight mounting



OCHIH UUH 33237. OR 2,0489763 SR July 28, 1936. 1 Q KARNES 2,048,703

SIGHT MOUNTING Filed Aug. 16, 1955 29 /7 f e .3l

24 7 Inventar" dames E- Karnes bmw 33. GEOMURSCAL INSU-inwind as.

Patented `Iuly 28, 1936 UNITED STATES PATENT OFFICE (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

5 This invention relates to a sight mounting for ordnance.

y Sight mountings of the type having a crossw levelling feature are arranged to receive the elet vat-ion movement of the gun in order to com- 10, pensate for the error caused by reason of elevatit ing' the gun on an inclined plane.

\ l.The purpose of this invention is to provide a sight mounting on this type which may be raised into firing position and lowered into a protected 15 position for travelling, and which is capable of receiving the elevation movement in any position lf of adjustment.

f With the foregoing and other objects in view,

t the invention resides in the novel arrangement 0. and combination of parts and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of the invention herein disclosed may be made within the scope of what is claimed without departing from the spirit of the invention.

A practical embodiment of the invention is illustrated in the accompanying drawing, Where- 1n:

Fig. 1 is a view in side elevation, with parts in section of a sight mounting constructed in accordance with the invention.

Fig. 2 is a sectional View on the line 2-2 of Fig. 1, and

Fig. 3 is a sectional view on the line 3--3 of Fig. 2.

Referring to the drawing, there is shown a sight mount comprising a standard 5 formed with a bearing 6 at its upper end for mounting a support shaft 'I. One end of the shaft projects from the bearing and terminally carries a pin 8 which constitutes the axis of cross level of the mount and is parallel to the axis of bore of the gun. An annular bearing member 9 is mounted 45 on the pin 8 and is embraced by an annular sight mount II) that is rotatable with respect thereto. The sight mount I carries a longitudinally disposed spirit level I I and it is provided with a bracket l2 for carrying a telescopic sighting instrument I3 including a transversely disposed spirit level I4.

The lower portion of the sight mount pivotally carries a worm-wheel sector I mounted to slide in the arm I6 of a rocker I1 which is mounted on the bearing 6 on the outer side of the standard 5. The arm I6 also carries a shaft I8 having a worm I9 in mesh with the sector I5 and serving to move the sight mount about the axis of cross level 8 to center the bubble of the spirit level I4.

The rocker I1 is formed with an arcuate rack 5 20 meshing with an operating shaft 2| carried by the standard 5. This mechanism is provided for the purpose of shifting the sight mount as an entity through a longitudinal angle to compensate for subsidence of the gun carriage or lack of'force and aft level as indicated by the spirit level II.

The standard 5 is arranged for movement diametrically of one of the gun trunnions 22 and to this end it` is mounted to slide in opposite grooves 23-23 in a bracket 24 which is secured to the gun carriage 25 below the trunnion 22. It is held in position of adjustment by means of a pair of set screws 26-25 threaded in the bracket and having their inner ends engageable 20 with a rib 21 on the standard.

A shaft 28 is arranged parallel to the standard and is carried on the inner side thereof, being mounted in an aperture 29 in the bearing 6 and in a bearing 3U at the lower end of the standard. 25 It is held against axial displacement relative to the standard by a pair of collars 3I-3I secured to the shaft and engaging the bearings.

A gearing wheel 32 loosely mounted on the shaft 28 and in driving engagement therewith 30 through a spline 33 is held in mesh with a segmental gear 34 keyed on the trunnion by means of an arm 35 rotatably mounted on the trunnion and retained in place against the carriage 25 by the gear 34.

A gear wheel 36 keyed on the upper end of the shaft meshes with a segmental gear 3'I keyed on the support shaft 1.

In the drawing the sight mounting is in substantially the highest position of adjustment 40 which is generally the firing position depending on the accommodation to the size of the operator and the conditions of cover. The mounting is readily lowered by loosening one of the set screws 26. In all positions the angular displacement of the trunnion during elevation of the gun is transmitted through the gearing 34, 32, 28, 36, and 31 to the support shaft 'l and axis of cross level 8. The correction for the errors caused by reason of elevating the gun on an inclined plane are therefore applied to the sight mounting irrespective of the position of adjustment of the standard.

I claim:

1. A carriage, a gun trunnion on the carriage, a bracket on the carriage below the trunnion, a standard slidably mounted in the bracket for movement diametrically of the trunnion, means for holding the standard in positions of adjustment, a support shaft in the upper end of the standard, a Ncross-*levelling sight mount gfiipiijghaft, a driven"sl1ft"'para11e1 with the standard and carried thereby, a gear wheel slidably engaging the driven shaft, a gear segment xed to the trunnion, an arm carried by the trunnion for holding said gear wheel in mesh with the gear segment, a gear wheel on the upper end of the driving shaft and a gear segment xed on the support shaft and meshing with said gear wheel.

2. A carriage, a gun trunnion on the carriage, a. standard slidably mounted on the carriage for movementI diametrically of the trunnion, means for holding the standard in positions of adjustment, a support shaft carried by the standard, a cross-levelling sight mount carried by the shaft, a driven shaft carried by the standard, means for driving said driven shaft from the trunnion in all positions of adjustment of the standard and a driving connection between the driven shaft and the support shaft whereby the trunnion and support shaft are synchronously rotated.

3. A carriage, a gun trunnion on the carriage, a standard slidably mounted on the carriage, means for holding the standard in positions of adjustment, a, support shaft carried by the standard, a cross-levelling sight mount carried by the shaft, a driven shaft carried by the standard, means for driving said driven shaft from the trunnion in all positions of adjustment of the standard and a driving connection between 5 the driven shaft and the support shaft whereby the trunnion and support shaft are synchronously rotated.

4. A carriage, a gun trunnion on the carriage, a standard slidably mounted on the carriage for movement diametricaliy of the trunnion, means for holding the standard in positions of adjustment, a sight support shaft carried by thestandard, a driven shaft carried by the standard, means for driving said driven shaft from the trunnion in all positions of adjustment of the standard and a driving connection between the driven shaft and the support shaft whereby the trunnion and support shaft are synchronously rotated.

5. A carriage, a gun trunnion on the carriage, a standard slidably mounted on the carriage, means for holding the standard in positions of adjustment, a sight support shaft carried by the standard, a driven shaft carried by the standard, means for driving said driven shaft from the trunnion in all positions of adjustment of the standard and a driving connection between the driven shaft and the support shaft whereby the trunnion and support shaft are synchronous- 1y rotated.

JAMES C. KARNES, 

